372 THE CONCEPT OF EVOLUTION 



that on his theory the process of evolution was none the less 

 continuous. The Ice Age, he said, introduced new factors 

 into the process of earth-sculpture, but there was no dis- 

 continuity. But ' spiritual influxes ' do not seem to be as 

 amenable to scientific treatment as glacial influences have 

 been. Wallace apparently thought of the material universe 

 being underpinned throughout by a spiritual universe, and 

 we have no right to object to that, but what the scientific 

 mind recoils from is the suggestion that a spiritual influx 

 occasionally operates dramatically, helping the organism over 

 difficult stiles, (c) It is possible that some of those who 

 hold by a ' spiritual influx ' theory mean little more than 

 those who are dissatisfied with a mechanistic evolutionism. 

 They recognise that more is involved in the evolving organ- 

 ism than is recognised by those who think that it can be 

 exhaustively summed up in terms of matter and motion. 

 In mankind we are sure that ideas count as a vera causa 

 in evolution; the question is how far biologists can discern 

 in animal evolution psychical factors that can be tested 

 and experimented with by appropriate methods. One of 

 the protagonists of the mechanistic interpretation of man 

 declares, without seeing the humour of it, that he can 

 demonstrate the physiological effects of an anticipation of 

 an operation. A mechanistic anticipation 1 



In seeking some reconciliation of religious conviction and 

 the results of science various attempts have been made, like 

 Wallace's, " to get past the scientific position without the 

 danger of being taken prisoner ". In regard to the worst 

 of these we quote Prof. G. J. Blewett (1907, p. 53) : 



" One of these attempts to ' get past the scientific position ' is so 

 fundamentally bad as to deserve special mention the endeavour to 

 justify belief in God by seeking to find gaps in the continuity of 



